The explosion is the latest deadly industrial incident in the world's largest producer of chemicals.

An explosion at a chemical plant in China has killed at least 19 people and injured 12 others, authorities said, in the latest industrial incident in the country.

The cause of Thursday's blast at Yibin Hengda Technology in an industrial park several hours southeast of Chengdu, the capital of the southwestern province of Sichuan, is not yet known, local officials said on Friday.

According to state news agency Xinhua, an investigation into the blast has begun.

A fire, which broke out early on Thursday evening due to the explosion, was put out by 11:30pm local time (3:30pm GMT), the government said in a statement.

Images on Chinese social media showed a huge fire and plumes of smoke rising from the facilities Thursday night.

A trio of three-storey buildings were reduced to their steel frames by the explosion, the Sichuan Daily newspaper said, citing witness accounts.

Windows of nearby buildings were shattered by the explosion at the factory, which is surrounded by a sand and gravel plant, it added.

The plant has three production lines, making 300 tonnes per year (tpy) of benzoic acid, which is used in food preservatives, and 2,000 tpy of 5-nitroisophthalic acid, for medicines and dyes, the regional environmental protection bureau, says.

China is the world's largest producer of chemicals.

Its breakneck pace of economic growth during the last decade has resulted in a spate of industrial accidents.

In 2015, an explosion in a chemical warehouse in the northern port city of Tianjin killed 165 people.

Last year, a blast at a petrochemical plant in eastern Shandong province killed eight people and injured nine.

The country has introduced measures to improve industrial safety over the last year, following incidents at coal mines and chemical plants.